Carriage for supporting lances in steel making operations



June 4, 1968 R. w. BROOKS ET 3,386,722

CARRIAGE FOR SUPPORTING LANCES IN STEEL MAKING OPERATIONS Filed May 27, 1965 I5 Sheets-Sheet l D:- 5, 2o A I /24 B [/9 A; -../"JO 1;? I /2/ l H /c/m/eo w. sew/(J, men/me F. KUBLJ'.

' 2o I; INVENTORS.

June 4, 1968 R.W. BROOKS ET AL 3,385,722

CARRIAGE FOR SUPPORTING LANCES IN STEEL MAKING QPERATIONS Filed May 27, 1965 5 Sheets-Sheet 2 INVENTORS 2/0/4420 w. seooxs,

H/QTf/UR E K0541.

June 4, 1968 w. BROOKS ET AL 3,386,722

CARRIAGE FOR SUPPORTING LANCES IN STEEL MAKING OPERATIONS 3 Sheets-Sheet 3 Filed May 27, 1965 United States Patent 3,386,722 CARRIAGE FOR SUPPORTING LANCES IN STEEL MAKING OPERATIONS Richard W. Brooks, 442 Bernice, Pittsburgh, Pa. 15237, and Arthur F. Kubli, 519 Cool Sh, Pitcairn, Pa. 15140 Filed May 27, 1965, Ser. No. 459,372 6 Claims. (Cl. 266--34) ABSTRACT OF THE DISCLOSURE This disclosure relates to an improved carriage for supporting a lance in the production of steel and more particularly, it relates to a safety device which insures that in the event of failure of the carriage raising and lowering mechanism, the carriage will become locked at a suitable level preventing damage to the plant equipment and injury to personnel. A safety feature is provided carriage-s for carrying lances in steel making operations wherein automatically operable means actuate stop members which can arrest the free fall of the carriage in the event of malfunctioning of the carriage lowering and raising apparatus. The mechanism can arrest the fall before excessive momentum develops in the fall.

In the art of making steel, it has become common to effect in the converting processes, a How of oxygen over the surface of the charge within the furnace during the steel making process. The process is sometimes referred to as the oxygen process and has been extensively used with success. It is the practice to supply the oxygen from a lance which is lowered into the furnace and directs the stream of oxygen against the upper surface of the charge during the steel making operation. The lance is raised and lowered between retracted and operative positions by means of a carriage, but should the suspending or elevator means for the carriage malfunction, considerable damage can be done to the equipment, causing substantial delays and extensive damage to the plant equipment and also present considerable hazards to operating personnel.

The principal object of the present invention is to provide a safety device which forms a part of the carriage means .for raising and lowering the lance in an oxygen process, and which automatically operates to suspend the lance in the event of malfunctioning of the elevator means and in this way circumvent costly and extensive damage to the steel making equipment and avoid dangerous working conditions for the operating personnel.

It is a further object of the present invention to provide an economical safety means which functions immediately upon malfunctioning of an elevator apparatus for restraining the carriage from dropping into the ladle and from causing damage to the steel making equipment which would otherwise occur byreason of such failures in the equipment.

It is a still further object of the present invention to provide an improve-d carriage means for an oxygen lance which incorporates an automatically operable retaining means and a series of stops which are spaced to provide coacting support surfaces for the anchoring means should there occur any malfunctioning of the elevator means for raising and lowering the said carriage means.

A further object of the present invention is to provide a sensitively operable actuating means for effecting locking of the carriage means but which does not itself sustain any of the supportive or impingement loads during operation of the locking means for retaining the carriage.

Other objects and features of the present invention will become apparent from a consideration of the following description, which proceeds with reference to the accompanying drawings, wherein:

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FIGURE 1 is an elevation view of a steel making furnace lance, and associated raising and lowering mechanism for the lance and incorporating the invention therein;

FIGURE 2 is an isometric view of the carriage and automatically operable means for supporting the carriage at a suitable vertical location on'the guide tracks should the elevator means fail;

FIGURE 3 is an enlarged front elevation view of the locking means of FIGURE 2, with the locking means illustrated in full line at carriage-locking position and in dotted line for retracted position thereof;

FIGURES 4 and 5 are section views taken on lines 44 and 55 respectively of FIGURE 3;

FIGURE 6 is an enlarged detail view of the suspending elements which raise and lower the carriage for sup porting the lance and which, in the event of failure, is supplanted by the anchoring means of FIGURES 2-5; and,

FIGURE 7 is a line diagram of the circuit for controlling the mechanism which operates the structure in FIGURES 2-5.

Referring now to the drawings, in steel making operation, the furance 10 is filled with a charge of material 12 and the open end 14 is shielded by a water-cooled shield cover 16 having an opening 17 through which is passed a lance 18 supported on a carriage 20 through mounting brackets 22, 24, holding the lance 18 perpendicularly. The carriage 20 is caused to move rectilinearly, by means of two pairs of spaced tracks 28, 30, which are carried by I beams or the like held outwardly from a support wall 31 (FIGURE 1) by support arms 34, 36, at the top and bottom ends of the beams 29, 31. Spaced guide wheels 40, 42 (FIGURE 4) are in engagement with the tracks 28, 30, and serve to guide precisely the vertical up and down movements of the carriage 20 and carry the lance 18 therewith so that at the full line position of the carriage 20 (FIGURE 1), the lance 18 is raised to its full line position, and at the dotted line position of the carriage, the lance 18 .is at its operative position, with the lower end extended into the brick lined furnace 10.

Spaced along the length of the I-beams 29, 31 are a number of paired stops 50, 52, (FIGURES 3, 4) which are welded through an intermediary to the webs 54 and flanges 44 of the I-beams. Should the support for the carriage for any rason fail, one or the other of these pairs of stops, 50, 52, serve to support the carriage 20 and lance 18 preventing them from falling through shield 16 and into the furnace 10 causing great damage to the steel making equipment and also causing hazardous explosions endangering working personnel.

The carriage 20 is suspended by a pair of cables 58, 60, which lead from a supply drum (not shown). The cables reaved over pulleys 61 (FIGURE 1), over pulley wheels 62 mounted on axles 64, passing between mounting flanges 66, and the cables 58, 60 (FIGURE 6) are then dead ended on a counterweighted lever 68, pivoted on pin 70 which serves as a fulcrum for the lever 68. Should unequal tension occur on cables 58, 60, one or the other of the ends of the lever 68 will engage and operate a coacting switch 72 or switch 74 on mountings 76 at the upper end of the tracks formed by the beams 29, 31, and operate locking means which are then used in place of the cables for supporting the carriage. The lever 68 is counterweighted so that should both cables 58, 60 fail, the lever 68 being overbalanced will operate one or the other of the switches 72, 74.

The carriage 20 is held squarely by diagonal guide rolls not shown which operatively engage beams 29, 31 to hold the carriage 20 squarely so that should the carriage fall, the line of movement is contained to a rectilinear path.

The carriage has a frame (FIGURE 3) and a pair of locking elements 92, 94, which are mounted for pivotal movement on axles 95, 96 which pass through depending arms 98 (FIGURE 3) having limit stops 100 which prevent rotation of the locking elements beyond the full line positions shown in FIGURE 3 so that the corners 104 of the locking elements will engage simultaneously the stops 50, 52, and thereby the weight of the carriage is transmitted through the axles 95, 96 onto the spaced stops 50, 52 through the corners 104 of the locking elements which are prevented from turning by engagement with stops 100 (FIGURE 3). The locking elements are pivoted to a retracted position, i.e., dotted line position wherein the corners 104 are out of engagement with the stops 50, 52 during vertically downward movement of the carriage. The dotted line position is produced for the locking elements only during operators actuation of the control mechanism for lowering the lance 18; at all other times the locking elements are in full line position. The dotted line position is effected by a drawing bar 102 which engages ends 103 of the locking elements and pivots them about 95, 96, to their dotted line positions. The drawing bar 102 is suspended on a rod 106 having a threaded end 108 with a nut 110 (FIGURE 2) which adjusts the position of the drawing bar 102 relatively to the locking elernents, causing them to be in light engagement when the locking elements are in full line positions.

The rod 106 is threadedly secured at 112 to a solenoid rod 114 which is operated by a solenoid 115. When the solenoid is not energized, the solenoid rod 114 is lowered together with the rod 106 and lift bar 102, the overbalanced weight of the locking elements 92, 98 causing them to pivot about their respective axles 95, 96, until they engage the stops 100 and the corners 104 thereof are in position to engage stops 50, 52, to lock the carriage against further downwardly movement (FIGURE 3).

The solenoid 115 is operated by one or the other of the switches 72, 74 (FIGURE 6) signalling slack in either one or both of the cables 58, 60 indicating a condition which means that the carriage is not properly supported and hence should not serve as the supportive structure. Under these circumstances, the lance should not be low ered to operating position. If either or both of the cables 58, 60 should break, one of the limit switch contacts 111, 113 (FIGURE 7) of limit switches 76 having switch arms 72, 74 (FIGURE 6) is opened to de-energize relay 117 and open switch 119 to de-energize solenoid 115 (FIGURE 7) breaking the circuit through conductor 124. The solenoid 115 can only be operated to closed position while contactor 119 is operatedto close switch 121 to energize solenoid during lowering of the carriage 20. At all other times, switch is opened and solenoid 115 is de-energized.

The electrical system described is such that upon sensing any malfunction of the cables which serve as the suspending means for the carriage 20, the solenoid will be tie-energized causing rod 106 and draw bar 102 to lower and the counterweighted locking elements 92, 94, will be rotated to the full line position where the outer corners 104 can engage and take support on the stops 50, 52 to halt downward movement of the carriage. This malfunction could arise by power failure, cable breakage, motor overspeed, or motor underspeed.

The frame 90 of the carriage (FIGURE 2) is rectangular and has both cross members 140 and vertical members 142 which provide a rigid box construction and the depending flanges 144, 146 which support the axles 95, 96, together with the depending yokes 150 provide sufficient rigidity and mechanical strength to withstand the impact force of the falling carriage which falls freely through a maximum distance defined by the vertical spacing between adjacent pairs of stops 50, 52.

During raising of the carriage, the solenoid 115 is at all times de-energized and the locking elements 92, 94 are in their full line positions, the inclined faces 160 (FIGURE 3) of the stops 50, 52 being engageable against inclined surfaces 162 of the locking elements 92, 94, as the elements pass the stops moving in an upward direction and causing them to pivot inwardly to the dotted line position. Consequently, the carriage can be freely raised by ratcheting of the locking elements over the stops 50, 52, and should there occur a failure of the cables during raising of the carriage, the locking elements are positioned to impinge with the stops and halt the downward movement of the carriage. Thus, during raising of the carriage, the safety is operative at all times. Also, an auxiliary lift mechanism can be used to raise the carriage independently of the cables because the locking elements will ratchet over the stops as the carriage is raised.

The structure for operating the locking elements 92, 94, does not sustain any of the load during arresting or supporting the vertical weight load of the carriage. Since none of the operating structure is subjected to such high orders of loads, then it can be made more sensitive and is less subject to breakage and malfunctioning.

In operation, when it is time for steel making operation to commence, the solenoid 115 is energized to pull the rod 106 and bar 102 upwardly (FIGURE 3) and holding the locking elements 92, 94, in the dotted line position, in which case the carriage can be freely lowered andthe locking elements will move past the stops 50, 52 without interference. The lance is lowered from the full line position of FIGURE 1 to the dotted line position of FIG- URE 1, at which point it can discharge oxygen and perform its steel making function. If, during lowering of the carriage there should occur any malfunctioning or breakage of one or both of the cables 58, 60 then one or the other of the switches 72, 74 will be operated because of turning of the counterweighted lever 68 in one direction or the other on its pivot 70 opening switch 111 or 113 (FIGURE 7) and operating auxiliary relay 117 to deenergize the solenoid 115. The counterweighted locking elements 92, 94 will then drop about their axles 96 to full line positions.

The locking elements engage stops of the yokes 150 and the corners 104 move out into engageable position with spaced stops 50, 52. The falling carriage will then be arrested by the corners 104 engaging the stops 50, 52 and the maximum free falling of the carriage that can occur is within the spacing of adjacent vertical stops. This vertical spacing is adjusted so that the free fall is arrested before the carriage and lance gain excessive momentum. There are sufficient pairs of spaced stops between the uppermost and lowermost positions of the carriage so that the carriage and lance can always be stopped at one or the other positions defined by the spaced stops between the uppermost and lowermost positions (FIGURE 1).

It is only during lowering of the lance that solenoid can be energized by closing switch 121 (FIGURE 7), at all other times, the solenoid is de-energized and the stop elements are in full line positions. During raising of the carriage, the stop elements ratchet over the stops as they move upwardly past the stops engaging the inclined faces 160, 162, in the stop and element respectively. The stop elements are thus at all times extended during carriage raising, to catch the carriage should the cables 58, 60 fail. The invention will function regardless of the occurrence or extent of build up of material on the lance 1 8 during steel making.

Although the present invention has been described in connection with certain selected example embodiments, it will be understood that these are illustrative of the invention and are by no means restrictive thereof. It is reasonably to be expected that those skilled in this art can make numerous revisions and adaptations of the invention to suit individual design requirements, and it is intended that such revisions and adaptations which incorporate the disclosed principles will be included within the scope of the following claims as equivalents of the invention.

What is claimed is:

1. A carriage for lance members in steel making operations comprising: a pair of tracks providing guide surfaces for vertical movement of the carriage which moves rectilinearly in prescribed vertical directions, a plurality of pairs of spaced stops disposed along the length of said tracks and providing arresting surfaces for engaging and holding said carriage, retractible anchorage means pivotally mounted on said carriage and overbalanced by the weight thereof and disposed between said carriage and tracks and successively engageable with said stops to define the vertical position of said carriage means, means for retracting said anchorage means to provide unimpeded vertical movement of said carriage means, means for suspending said carriage means and effecting raising and lowering thereof, and balanced means operatively secured to said suspending means and adapted to become unbalanced responsively to the tension in said suspending means, and means responsive to said balanced means as it becomes unbalanced to operate said retracting means whereby the anchorage means are operated.

2. Safety means for use in supporting apparatus in steel making operations comprising: guide means having a plurality of spaced apart stops which form support surfaces therein, carriage means for mounting a steel processing structure thereon and including portions in coacting relation with said guide means, flexible supporting means for raising and lowering said carriage means, balanced means operatively secured to said supporting means and responsive to failure thereof, retractible anchoring means forming a releasable connection between said carriage means and said spaced apart stops, means responsive to said balanced means which is actuated by change of the tension of said supporting means to allow the anchoring means to pivot into an extended position to effect automatic extending operation of said anchoring means whereby said carriage means is arrested by adjacent ones of said stops if said supporting means fail, and means for maintaining said anchoring means in a normally retracted position to permit unimpeded lowering of said carriage means.

3. Safety means for use in supporting apparatus in steel making operations comprising: guide means having a plurality of spaced apart stops which form support surfaces therein, carriage means for mounting a.steel processing structure thereon and including portions in coacting relation with said guide means, flexible supporting means for raising and lowering said carriage means, balanced means operatively secured to said supporting means and responsive to failure thereof, retractible anchoring means forming a releasable connection between said carriage means and said spaced apart stops, means responsive to said balanced means which is actuated by change of the tension of said supporting means to effect automatic extending operation of said anchoring means whereby said carriage means is arrested by an adjacent one of said stops if said supporting means fail, means for maintaining said anchoring means in a normally retracted position to permit unimpeded lowering of said carriage means, and means pivotally supporting said anchoring means which are rotated under their own weight in a direction wherein a portion thereof is moved outwardly into engageable relation with a coacting one of said anchoring means.

4. Safety means for use in supporting apparatus in steel making operations comprising: guide means having a plurality of spaced apart stops which form support surfaces therein, carriage means for mounting a steel processing structure thereon and including portions in coacting relation with said guide means, supporting means for raising and lowering said carriage means, balanced means operatively secured to said supporting means and responsive to failure thereof, retractible anchoring means forming a releasable connection between said carriage means and said spaced apart stops, means responsive to said balanced means which is actuated by change of the tension of said supporting means to effect automatic extending operation of said anchoring means whereby said carriage means is arrested by an adjacent one of said stops if said supporting means fail, means for maintaining said anchoring means in a normally retracted position to permit unimpeded lowering of said carriage means, means pivotally supporting said anchoring means which are rotated under their own weight in a direction wherein a portion thereof is moved outwardly into engageable relation with a coacting one of said anchoring means, said anchoring means being spaced apart by amounts permitting the carriage to fall only through the limited distance between adjacent stops wherein the cushioning is within the strength limitation of said anchor and coacting stop.

5. Safety means for use in supporting apparatus in steel making operations comprising: guide means having a plurality of spaced apart stops which form support surfaces therein, carriage means for mounting a steel processing structure thereon and including portions in coacting relation with said guide means, flexible supporting means for raising and lowering said carriage means, balanced means operatively secured to said supporting means and responsive to failure thereof, retractible anchoring means forming a releasable connection between said carriage means and said spaced apart stops, means responsive to said balanced means which is actuated by change of the tension of said supporting means to effect automatic extending operation of said anchoring means whereby said carriage means is arrested by an adjacent one of said anchoring means in a normally retracted position to permit unimpeded lowering of said carriage means, and means pivotally supporting said anchoring means which are rotated under their own weight in a direction wherein a portion thereof is moved outwardly into engageable relation with a coacting one of said anchoring means and means defining the position of said anchoring means in the position wherein they support said carriage means, and means for actuating said anchoring means within the time interval provided for falling movement between adjacent anchoring stops.

6. A safety device for retaining carriages which are vertically movable in steel making operations comprising: a guide means for directing the raising and lowering movements of the carriage, a plurality of spaced abutment members providing a combination stops and resting surfaces, ratcheting means having complementary surfaces which form anchoring abutments coacting with said respectively spaced stops, means for retracting said anchoring means during raising of the carriage, means for extending said anchoring means during lowering of the carriage and responsive to malfunctioning of said carriage to prevent falling beyond the limits defined by the spacing of vertically adjacent stop means, and means for providing normally extended positions for said anchoring means which include conjunction with said stop means, camming surfaces permitting free vertical movement of said anchoring means past the complementary coacting stops.

References Cited UNITED STATES PATENTS 758,470 4/ 1904 Pollock 187-82 2,403,333 7/1946 Bjerke 187-82 3,025,047 3/ 1962 Reinfeld et al. 26634 3,170,977 2/ 1965 Obenchain 26634 I. SPENCER OVERI-IOLSER, Primary Examiner.

E. MAR, Assistant Examiner. 

